The invention relates to a chain lock for round steel chains.
In the state of the art, DE 197 43 025 C1 discloses a block connecting link for round steel chains having two identical link halves. Each link half has a substantially rectangular cross-section with a straight rear surface, plane side surfaces, convexly curved end surfaces, and receptacles for steel chain links located next to the transverse middle plane and facing the center parting plane. Provided on one end of each link half is a projection having a bracket protruding towards the neighboring end surface, and provided on the other end is a projection having a recess that conforms to the bracket. A pin protrudes at the projection having the recess for engagement into a pocket next to the projection. The principal axes of the bracket, recesses, pins and pockets extend at an angle in relation to the transverse middle plane. A supporting cam is provided between the receptacles of each link half. In the case of this block connecting link, all pin-type connections contribute to receiving the longitudinal forces, to achieve a high breaking force and a high number of stress reversals. It was determined, however, that the locking pins respectively arranged at the ends and driven into the pin via cross bores are also subjected to high shear stress. On the other hand, interlocking at the ends shall not be forgone so that the link halves may not easily spread apart under load stress.
DE 20 2004 009 459 U1 describes a chain lock for steel links chains having two identical chain lock parts that can be mounted to each other in the longitudinal direction and that are arranged in a rotationally symmetric manner. Each lock part includes a center bar extension to form a center bar when the lock parts are mounted to each other. The arc sections at the ends of each lock part respectively form one of two complementary coupling members. Locking pins that are introduced into corresponding bores effectuate the interlocking of the lock halves in the area of the center bar. Undercut interlocking bars are respectively formed in the end sections, wherein the interlocking bars engage into a correspondingly configured pocket of the other lock part. As a result of the undercut at the interlocking bars and the pocket provided for receiving the interlocking bar, the lock parts are interlocked. The interlocking bar and the interlocking pocket, respectively, transfers the tensile forces exerted on the chain lock to the respective other lock half so that the interlocking bars assume a dual function because they simultaneously prevent the lock halves from separating from each other transversely to the longitudinal extension.